A color filter used in the liquid crystal display device is provided with a light-shielding film known as a black matrix for the purpose of improving the contrast by shielding light between colored pixels, or the like. Furthermore, in a solid-state image sensing device, a light-shielding filter film is provided for the purpose of preventing generation of noise due to shielding light on the back side or shielding light in the infrared region between pixels, improving image quality, or the like.
As a composition for forming a black matrix for a liquid crystal display device or a light-shielding filter film (light-shielding film) used in a solid-state image sensing device, a photosensitive resin composition containing a black coloring material such as carbon black, black titanium, and the like is known.
Specifically, for example, there have been suggested a photosensitive resin composition containing a black titanium, which has a specific X-ray diffraction peak intensity ratio for improvement of an optical density or the like (see, for example, Japanese Patent No. 3724269 and the pamphlet of International Publication No. 2005/037926), and a photosensitive resin composition containing a black titanium, which has a specific nitrogen concentration or a specific crystallite diameter (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2006-182627, JP-A No. 2006-206891, and JP-A No. 2006-209102) as a photosensitive resin composition. Further, as the light-shielding materials, there have been disclosed a pigment-dispersed composition containing a pigment mixture composed of an organic pigment and a titanium oxide pigment, and/or titanium oxynitride (see, for example, JP-A No. 10-1626).
Further, in the solid-state image sensing device, above a microlens disposed on a color filter and a light-receiving element for receiving light via the color filter, a light-transmitting optical member having a light-shielding section for reduction in the amount of light incident on the device, control of the optical path, or the like is generally disposed. In such an optical member, a light-shielding section is formed and the light-shielding section is formed, for example, by vapor-depositing a metal film in a region other than a light-transmitting section, forming a black film using a resist material including a black agent such as carbon black and the like, etc.
Conventionally, a film containing carbon black has been widely used since it can provide high light-shielding concentrations across a wide range of the wavelength regions. The optical density of the film containing carbon black increases gradually from a long-wavelength side to a short-wavelength side, and accordingly, the optical density in a short-wavelength region is extremely high, as compared with the long-wavelength side. As a result, there is a tendency that upon pattern exposure with light in the ultraviolet region such as, for example, a g-ray, an h-ray, an i-ray, and the like at a time of preparation, light does not reach the inside of the film, and exposure is insufficient, thereby easily leading to deterioration of the pattern shape or peeling.
Titanium black has a light-shielding property for shielding long-wavelength light in the infrared region or the like, but can transmit light on a short-wavelength side. As a result, pattern exposure can be carried out well with light in the ultraviolet region. However, in fact, regarding a color colored black with titanium-containing black pigment, its transmittance region also encompasses the visible region (400 to 700 nm). Thus, the light-shielding property in the visible region is easily reduced, as compared with widely used carbon black, and the transmitted light may be noise on a device in some cases.
Furthermore, if a film is formed by vapor deposition, there is a problem that the film surface is warped due to shrinkage and thus easily causes poor adhesion, in addition to a problem that the step is complicated. Further, the vapor-deposited film has a light reflecting property, which may cause concern about its side effects.
On the other hand, recently, size reduction of the solid-state image sensing device has been particularly promoted. In the color filter for a solid-state image sensing device, there is a demand for a thinner layer (for example, a thickness of 1 μm or less) of a colored pattern, and there is also a demand for technology corresponding to a thinner film for a light-shielding film.